Prof

Tadashi Aotsuka

e-mail

aotsuka@tmu.ac.jp

Prof

Koichiro Tamura

e-mail

ktamura@tmu.ac.jp

Molecular Phylogenetics and Biogeography of Drosophila species

Fruit flies (Drosophila) are ideal for studying adaptive evolution, since they have adapted to various environments on Earth. Their ancestors emerged in the early Cenozoic era in Southeast Asia and subsequently expanded their distribution throughout the Holarctic region. Taking advantage of abundant information and availability of advanced experimental techniques, we are studying the evolution of fruit flies with a focus on biodiversity in the Asian green belt.

Genetic Diversity in Animal Populations

Various organisms living in Japan show geographic variations based on genetic diversity. Such genetic diversity among populations developed due to geological and climatic changes during the Cenozoic era in many species. Examining geographic variations in DNA sequences and karyotypes among natural populations of various species, we are studying the effects of environmental changes on their speciation and evolution.

Molecular Evolution of DNA Sequences and Bioinformatics

Genome sequencing projects have produced large amounts of DNA sequence data. Analyzing these data together with our original sequence data by computational and bioinformatic techniques, we are studying how DNA sequences, genes and genomes evolve. We are also developing new theoretical methods and computer software for molecular evolutionary and phylogenetic analyses.

Related Links

Recent Publications

1. Kitamura N, Fujiyama S, Aotsuka T (2008) Rapid chromosomal changes inferred from variation in mitochondrial DNA among populations of the leaf beetle Chrysolina aurichalcea (Coleoptera: Chrysomelidae) in Japan. Zoological Science 25, 1111-1120
2. Kumar S, Nei M, Dudley J, Tamura K (2008) MEGA: A biologist-centric software for evolutionary analysis of DNA and protein sequences. Brief Bioinform, 9:299–306.
3. Naruse T, Segawa RD, Aotsuka T. Two new species of freshwater crab (Crustacea: Decapoda: Potamidae) from Tokashiki Island, central Ryukyu Islands, Japan. Systematics and Biodiversity 5:409-415. 2007.
4. Tamura K, Dudley J, Nei M, Kumar S. MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) Software Version 4.0 Mol. Biol. Evol. 24:1596-1599. 2007.
5. Gao J, Watabe H, Aotsuka T, Pang J, Zhang Y. Molecular phylogeny of the Drosophila obscura species group, with emphasis on the Old World species. BMC Evol. Biol. 7 art. no. 87. 2007.
6. He L, Watabe H, Xiangyu J, Gao J, Liang X, Aotsuka T, Zhang Y. Genetic differentiation and cryptic speciation in natural populations of Drosophila lacertosa. Mol. Phyl. Evol. 43:24-31. 2007.
7. Wang B, Park J, Watabe H, Gao J, Xiangyu J, Aotsuka T, Chen H, Zhang Y. Molecular phylogeny of the Drosophila virilis section (Diptera: Drosophilidae) based on mitochondrial and nuclear sequences. Mol. Phyl. Evol. 40:484-500. 2006.
8. Takamori H, Watabe H, Fuyama Y, Zhang Y Aotsuka T. Drosophila subpulchrella, a new species of the Drosophila suzukii species-subgroup from Japan and China (Diptera, Drosophilidae). Entomological Science 9:121-128. 2006.
9. Nozawa M, Kumagai M, Aotsuka T, Tamura K. Unusual evolution of interspersed repeat sequences in the Drosophila ananassae subgroup. Mol. Biol. Evol. Mol Biol Evol. 23:981-987. 2006.
10. Nozawa M, Aotsuka T, Tamura K. A novel chimeric gene, siren, with retroposed promoter sequence in the Drosophila bipectinata complex. Genetics 171: 1719-1727. 2005.
11. Saito S, Tamura K, Aotsuka T. Replication origin of mitochondrial DNA in insects. Genetics 171: 1695-1705. 2005.
12. Segawa RD, Aotsuka T (2005). The mitochondrial genome of the Japanese freshwater crab, Geothelphusa dehaani (Crustacea: Brachyura): evidence for its evolution via gene duplication. Gene. 2005 Aug 1;355:28-39.
13. Chen, H-W, Watabe H, Gao J-J, Takamori H, Zhang Y-P, Aotsuka T (2005). Species diversity of the subgenus Amiota (s. str.) Loew, (Diptera, Drosophilidae) in southern China. Journal of Natural History 39(3):265-310.
14. Chen H-W, Aotsuka T (2004). A survey of the genus Stegana Meigen from southern Japan (Diptera, Drosophilidae), with descriptions of three new species. Journal of Natural History 38:2779-2788.
15. Tamura K, Nei M, Kumar S (2004). Prospects for Inferring Very Large Phylogenies Using the Neighbor-Joining Method. Proc. Nat. Acad. Sci. USA 101: 11030-11035.
16. Gao J-J, Watabe H, Zhang Y-P, Aotsuka T (2004). Karyotype Differentiation in Newly Discovered Members of the Drosophila obscura Species Group from Yunnan, China. Zoological Research 25:236-241.
17. Kumar S, Tamura K, Nei M (2004). MEGA3: Integrated software for molecular evolutionary genetics analysis and sequence alignment. Brief. Bioinformatics 5:150-163.
18. Tamura K, Subramanian S, Kumar S (2004) Temporal patterns of fruit fly (Drosophila) evolution revealed by mutation clocks. Mol. Biol. Evol. 21: 36-44.
19. Naruse T, Segawa R. Shokita S (2004). Amamiku, a new genus for the true freshwater crab, Candidiopotamon amamense Minei, 1973 (Decapoda: Brachyura: Potamidae), from the Central Ryukyu Islands, Japan. Zootaxa 653: 1?8.
20. He L-P, Watabe H, Zang Y-P, Aotsuka T (2003). Karyotype differentiation and reproductive isolation among natural populations of Drosophila lacertosa. Cell Research 13:491-497.
21. Gao J-J, Watabe H, Toda MJ, Zhang Y-P, Aotsuka T (2003). The Drosophila obscura species-group (Diptera, Drosophilidae) from Yunnan province, southern China. Zool. Sci. 20:773-782.
22. Chen H-W, Aotsuka T (2003) A survey of the genus Leucophenga (Diptera, Drosophilidae) in Iriomote-jima of Japan, with Descriptions of Three New species. The Canadian Entomologist 135:1-16.
23. Kawasaki D, Aotsuka T, Higashinakagawa T, Ishii S (2003) Cloning of the genes for the pituitary glycoprotein hormone alpha and follicle-stimulating hormone beta subunits in the Japanese crested ibis, Nipponia nippon. Zool Sci. 20(4):449-59.
24. Kawasaki D., Aotsuka T, Higashinakagawa T, Ishii S (2003) Cloning of the gene for the thyrotropin beta subunit in the Japanese crested ibis, Nipponia nippon. Zool Sci. 20(2)):203-10.
25. Tamura K, Kumar S (2002) Evolutionary distance estimation under heterogeneous substitution pattern among lineages. Mol. Biol. Evol. 19:1727-36.